Caseback corrosion repair

[jdm]

This is typical with diver's that are used at sea but then not rinsed in fresh water and inspected every few months. Having got a micro lathe I finally could repair it.

 

Holding the piece is the easy part as the chuck grabs the inside nicely, I placed a live center just for safety.

I used a parting tool first but the cutting profile was all wrong. Getting there anyway

I reground the tool with all the right angles but it became blunt quickly, I will try hardening it the next time.

Trying various speeds etc, I couldn't get a finish better than below

The crown was in a sorry state too. It cleaned quite good with an ammonia solution, but in the end it was replaced anyway as soment went at with pliers. Luckily I had a spare from an NH36 swap.

5 minutes @ 6BAR, all is good.

[oldhippy]

Good work. I’m a little surprised its still waterproof.

[jdm]

9 minutes ago, oldhippy said:

Good work. I’m a little surprised its still waterproof.

No reason it shouldn't be. You are looking at very magnified pictures where any minuscule defect is exaggerated. And thick O-rings like Seiko uses work wonders, as anyone that had a change to work with will find.

[oldhippy]

You are looking at very magnified pictures. I;m fully aware of that. You can only use the right gasket, any other will cause leakage. I think its great you have managed to do such a good job.